i have 4 angels 2 are a little bigger than quarter size(their body size)and the other two smaller than a quarter, i need to know how old they are about and when can they start to breed if i think i have a pair? also if they are a pair (they are in a 15 gallon tank by them selves and when we bought the other two and put them in there the one was gaurding the other one, so we put the two new ones in a different tank) do they do that sometimes even though i dont think they are old enough to breed? i have done research and i cant find to much about breeding ages and stuff.

I am no expert on Angels, but I have had a couple spawn.  It is not too hard to get them to spawn IF you have a pair, the difficulty is in hatching the eggs and raising the fry.  If you are successful in the hatch, and they live more than a few days, you will may have MANY babies to deal with.  You will need lots of tanks to hold them all and a way to grow tiny live food.  They need to be fed several times a day.

Angelfish mature around 8 to 12 months old.  Most get large.  Mine were about the size of an adult's hand. I have had two in a 29 gallon spawn for me.  The tank was heavily planted.  They love large Amazon sword plants.  Many people also use a long piece of flat slate-rock set at an angle.

From the size of your fish, it sounds like you have several more months to wait before they are mature. If you want them to spawn, I would put the 4 back together in the tank and let them grow up.  That way you have a better chance that you will get male/female. As the months go by, you will need a much larger tank than a 15 gallon.  2 large angels in a 29 gallon is just about right.

Here is a website about Angels:

angelfish.info/

There are many more on the web. Go to Google.com and enter "Breeding Angelfish".

Here is a pic of one of the pairs that spawed for me.  This is an old picture from 2003. The babies did hatch, but only lived a few days.

mine look a lot like yours -the one i think is the male looks like your black one and the other is white without strips (a silver probabily)

The pair in the picture is opposite.  The "Marbled" one is the female, the male is the standard "Silver" (silver with black stripes).